This invention relates to the installation of underwater pipe and, more particularly, to an anchoring device useful for supporting pipe which runs underwater.
Mechanical anchoring devices are designed to support underwater pipe against buoyancy, axial and lateral movement and sagging. Since underwater pipe is formed of a rigid material which has a relatively limited range of movement before it ruptures or tears loose from its terminal such as a drilling platform or the like, anchoring devices have been developed to engage the pipe and restrain it against unacceptable movement.
Installation of anchoring mechanisms used in the past is a time-consuming operation which in many cases requires the assistance of one or more divers. Since underwater divers are expensive, diver time must be kept to a minimum in order to maintain installation expenses within reasonable limits.
Anchoring devices of the type used in the past have normally included a curved plate to engage the upper pipe surface and anchoring devices connected to portions of the plate which project from both sides of the plate, which are drilled into the underwater surface for holding the plate in place. A piece of angle iron or a bar was either welded or bolted to the upper plate for engaging the lower surface of the pipe. In the case where bolts were used, pressure was not uniformly applied to the pipe surface causing the coating to chip when the bolts were tightened. Both the welding operation and installation of the four bolts which were normally used are time-consuming and expensive when done underwater.